Lead-free bismuth-free silicon-free brass

ABSTRACT

The invention relates to a lead-free bismuth-free silicon-free brass alloy, comprising: by the total weight of the brass alloy, 60-65 wt % copper, 0.01-0.15 wt % antimony, 0.1-0.5 wt % magnesium, one or more element selected from the group consisting of 0.1-0.7 wt % aluminum, 0.05-0.5 wt % tin, 0.05-0.3 wt % phosphorus, 0.05-0.5 wt % manganese and 0.001-0.01 wt % boron, and a balance of zinc. The brass alloy of the invention does not adopt lead, thus avoiding lead pollution. Besides, neither bismuth nor silicon is adopted, thus enabling the brass alloy to have an improved cutting performance.

CROSS-REFERENCE TO RELATED APPLICATION

This application is the U.S. national phase of International Application No. PCT/CN2014/074942, filed on Apr. 9, 2014, which claims the priority benefit a Chinese Patent which is application No. 201410003372X, filed on Jan. 3, 2014. The entire contents of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The invention relates to an environmentally friendly brass alloy, and particularly to a free cutting and dezincification resistant brass alloy.

Background of Invention

Generally, the brass for processing is added with metallic zinc by a percentage of 38-42%. In order to make it easy to process brass, brass usually contains 2-3% lead to enhance strength and processability. Lead-containing brass has excellent moldability (making it easy to fabricate products of various shapes), cutting performance, and abrasion resistance, so that it is widely applied to mechanical part with various shapes, accounts for a large proportion in the copper industry, and is well known as one of the most important basic material in the world. However, during the production or use of lead-containing brass, lead tends to dissolve in the solid or gas state. Medical studies have shown that lead can bring about substantial damage to the human hematopoietic and nervous systems, especially children's kidneys and other organs. Many countries in the world take the pollution and hazard caused by lead very seriously. The National Sanitation Foundation (NSF) sets a tolerance of lead element of 0.25% or less. Organizations like the Restriction of Hazardous Substances Directive (RoHS) of European Union successively stipulate, restrict and prohibit the usage of brass with a high lead content.

Furthermore, when the zinc content in brass exceeds 20 wt %, the corrosion phenomenon of dezincification is prone to occur. Especially when brass is exposed to the chloride rich environment, e.g. marine environment, the occurrence of corrosion phenomenon of dezincification may be accelerated. Dezincification may severely destroy the structure of brass alloy, so that the surface strength of brass products is reduced and the brass tube even perforates. This greatly reduces the lifetime of brass products and causes problems in application.

Therefore, there is a need to provide an alloy formula for solving the above problems, which can replace the brass with a high lead content, is dezincification corrosion resistant, and further has excellent casting performance, forgeability, cutting performance, corrosion resistance and mechanical properties.

BRIEF SUMMARY OF THE INVENTION

As known in the prior art, silicon may appear in the alloy metallographic structure as y phase (sometimes as κ phase). In this case, silicon may replace the function of lead in the alloy to an extent, and improve cutting performance of the alloy. Cutting performance of the alloy increases with the content of silicon. However, silicon has a high melting point and a low specific gravity and is prone to be oxidized. As a result, after silicon monomer is added into the furnace in the alloy melting process, silicon floats on the surface of alloy. When the alloy is melt, silicon will be oxidized into silicon oxides or other oxides, making it difficult to produce silicon-containing copper alloy. In case silicon is added in the form of Cu—Si alloy, the economic cost is increased.

Bismuth can be added to replace lead for forming cutting breakpoints in the alloy structure to improve cutting performance. However, thermal cracking is prone to occur during forging in case of a high bismuth content, which is not conducive for producing.

Thus, it is an object of the invention to provide a brass alloy which exhibits excellent performance like tensile strength, elongation rate, dezincification resistance and cutting performance, which is suitable for cutting processed products that require high strength and wear resistance, and which is suitable for constituent materials for forged products and cast products. The brass alloy of the invention can securely replace the alloy copper with a high lead content, and can completely meet the demands about restrictions on lead-containing products in the development of human society.

To achieve the above object, the inventors have proposed the following lead-free bismuth-free silicon-free brass alloy.

A lead-free bismuth-free silicon-free brass alloy with excellent cutting performance (hereinafter referred to as the inventive product 1) comprises: by the total weight of the brass alloy, 60-65 wt % copper, 0.01-0.15 wt % antimony and 0.1-0.5 wt % magnesium, and a balance of zinc.

In the inventive product 1, lead, silicon, and bismuth is absent, the content of copper is controlled at 60-65 wt %, and a small quantity of antimony and magnesium is added to form intermetallic compounds with copper, so that cutting performance of the alloy is improved and dezincification resistance of the alloy is simultaneously improved. In other words, in the inventive product 1, the cutting performance is improved by adding antimony and magnesium to form γ phase. The metallographic structure of the alloy mainly comprises α phase, β phase, γ phase, and soft and brittle intermetallic compounds which are distributed in grain boundaries or grains. Copper and zinc make main constituents of the brass alloy. By adding antimony and magnesium, not only the cutting performance of the alloy is improved, but also the dezincification resistance is improved.

When the content of antimony is lower than 0.01 wt %, and the content of magnesium is lower than 0.1 wt %, the resulting alloy has a cutting performance which is not acceptable in the industrial production. The cutting performance of the alloy will increase with the content of antimony and magnesium. However, when the content antimony in the alloy is 0.15 wt % and the content of magnesium is 0.5 wt %, improvement in the cutting performance of the alloy reaches the saturated state.

A lead-free bismuth-free silicon-free brass alloy with excellent cutting performance (hereinafter referred to as the inventive product 2) comprises: by the total weight of the brass alloy, 60-65 wt % copper, 0.01-0.15 wt % antimony, 0.1-0.5 wt % magnesium, and further comprises, by the total weight of the brass alloy, 0.05-0.3 wt % phosphorus and/or 0.05-0.5 wt % manganese, and a balance of zinc.

As compared with the inventive product 1, the inventive product 2 is further added with 0.05-0.3 wt % phosphorus and/or 0.05-0.5 wt % manganese by the total weight of the brass alloy. Although phosphorus can't form γ phase, phosphorus has a function of facilitating a good distribution of γ phase for antimony and magnesium, thus increasing cutting performance of the alloy. Meanwhile, in case phosphorus is added, γ phase will disperse crystal grains of the primary α phase, thus increasing casting performance and corrosion resistance of the alloy. When the content of copper, antimony, and magnesium is 60-65 wt %, 0.01-0.15 wt %, and 0.1-0.5 wt %, respectively, and the content of phosphorus is lower than 0.05 wt %, phosphorus can not play its role effectively. While when the content of phosphorus is higher than 0.3 wt %, casting performance and corrosion resistance of the alloy will be degraded. Adding manganese helps to improve dezincification resistance and cast flowability of the alloy. When the content of manganese is lower than 0.05 wt %, manganese can not play its role effectively. While when the content of manganese is 0.5 wt %, manganese can play its role to the saturation value.

A lead-free bismuth-free silicon-free brass alloy with excellent cutting performance (hereinafter referred to as the inventive product 3) comprises: by the total weight of the brass alloy, 60-65 wt % copper, 0.01-0.15 wt % antimony, 0.1-0.5 wt % magnesium, and further comprises, by the total weight of the brass alloy, 0.05-0.5 wt % manganese, 0.1-0.7 wt % aluminum, 0.05-0.5 wt % tin, 0.05-0.3 wt % phosphorus and/or 0.001-0.01 wt % boron, and a balance of zinc.

As compared with the inventive product 1, the inventive product 3 is further added with 0.05-0.5 wt % manganese, 0.1-0.7 wt % aluminum, 0.05-0.5 wt % tin, 0.05-0.3 wt % phosphorus and/or 0.001-0.01 wt % boron by the total weight of the brass alloy.

Adding tin into the alloy also intends to form y phase, thus increasing cutting performance of the alloy. Besides, adding tin obviously increases strength, plasticity, and corrosion resistance the alloy. However, since adding tin may increase cost, aluminum is added along with tin. As a result, not only cutting performance of the alloy can be improved, but also strength, wear resistance, cast flowability, and high temperature oxidation resistance of the alloy can be increased. In order to make a better use of the above effects, the content of tin and aluminum is 0.05-0.5 wt % and 0.1-0.7 wt %, respectively. Meanwhile, the alloy is further added with trace boron so as to increase corrosion resistance of the alloy. By adding boron, it is possible to better suppress alloy dezincification, increase the mechanical strength, and simultaneously alter defect structure of cuprous oxide film on the surface of copper alloy, thus forming a cuprous oxide film which is more uniform, dense, and stain resistant. When the content of boron is lower than 0.001 wt %, boron can't play its role as mentioned above. While when the content of boron is higher than 0.01 wt %, the above performance can't be further increased. Thus, the optimum content of boron is 0.001-0.01 wt %. The content of phosphorus and manganese has the same interval as that of the inventive product 2, and this is based on the same reason as that of the inventive product 2. Whether antimony, magnesium, aluminum, tin, phosphorus, manganese and/or boron should be added depends on the requirement for cutting performance of various products.

A lead-free bismuth-free silicon-free brass alloy with excellent cutting performance (hereinafter referred to as the inventive product 4) comprises: by the total weight of the brass alloy, 60-65 wt % copper, 0.01-0.15 wt % antimony, 0.1-0.5 wt % magnesium, and further comprises, by the total weight of the brass alloy, 0.05-0.5 wt % manganese, 0.1-0.7 wt % aluminum, 0.05-0.5 wt % tin, 0.05-0.3 wt % phosphorus and/or 0.001-0.01 wt % boron, and a balance of zinc, wherein the total content of manganese, aluminum, tin, phosphorus and/or boron is not larger than 2 wt % of the total weight of the brass alloy.

A lead-free bismuth-free silicon-free brass alloy with excellent cutting performance (hereinafter referred to as the inventive product 5) comprises: by the total weight of the brass alloy, 60-65 wt % copper, 0.01-0.15 wt % antimony, 0.1-0.5 wt % magnesium, and further comprises, by the total weight of the brass alloy, 0.05-0.5 wt % manganese, 0.1-0.7 wt % aluminum, 0.05-0.5 wt % tin, 0.05-0.3 wt % phosphorus and/or 0.001-0.01 wt % boron, and a balance of zinc, wherein the total content of manganese, aluminum, tin, phosphorus and/or boron is 0.2-2 wt % of the total weight of the brass alloy.

A lead-free bismuth-free silicon-free brass alloy with excellent cutting performance (hereinafter referred to as the inventive product 6) comprises: by the total weight of the brass alloy, 60-65 wt % copper, 0.01-0.15 wt % antimony, 0.1-0.5 wt % magnesium, and further comprises, by the total weight of the brass alloy, 0.05-0.5 wt % manganese, 0.1-0.7 wt % aluminum, 0.05-0.5 wt % tin, 0.05-0.3 wt % phosphorus and/or 0.001-0.01 wt % boron, and a balance of zinc and unavoidable impurities, wherein the unavoidable impurities comprise: by the total weight of the brass alloy, 0.25 wt % or less nickel, 0.15 wt % or less chrome and/or 0.25 wt % or less iron.

As compared with the inventive product 3, the inventive product 6 further comprises some unavoidable impurities, i.e., mechanical impurities of nickel, chrome and/or iron.

A lead-free bismuth-free silicon-free brass alloy with excellent cutting performance (hereinafter referred to as the inventive product 7) comprises: by the total weight of the brass alloy, 60-65 wt % copper, 0.05-0.5 wt % tin, and two or more elements selected from the group consisting of, by the total weight of the brass alloy, 0.1-0.7 wt % aluminum, 0.05-0.3 wt % phosphorus and 0.05-0.5 wt % manganese, and a balance of zinc.

In case that neither antimony nor magnesium is present, adding 0.05-0.5 wt % tin of the total weight of the alloy can still meet the needs for cutting performance in the industrial production. The content of tin to be added has the same interval as that of the inventive product 3, and this is based on the same reason as that of the inventive product 3. Whether aluminum, phosphorus, and manganese should be added depends on the requirement for cutting performance of various products. The content to be added has the same interval as that of the inventive product 3, and this is based on the same reason as that of the inventive product 3.

A lead-free bismuth-free silicon-free brass alloy with excellent cutting performance (hereinafter referred to as the inventive product 8) comprises: by the total weight of the brass alloy, 60-65 wt % copper, 0.05-0.5 wt % tin, and two or more elements selected from the group consisting of, by the total weight of the brass alloy, 0.1-0.7 wt % aluminum, 0.05-0.3 wt % phosphorus, and 0.05-0.5 wt % manganese, and further comprises, by the total weight of the brass alloy, 0.01-0.15 wt % antimony, 0.1-0.5 wt % magnesium and/or 0.001-0.01 wt % boron, and a balance of zinc.

Whether antimony, magnesium, aluminum, tin, phosphorus, manganese and/or boron should be added depends on the requirement for cutting performance of various products. The content to be added has the same interval as that of the inventive product 3, and this is based on the same reason as that of the inventive product 3.

A lead-free bismuth-free silicon-free brass alloy with excellent cutting performance (hereinafter referred to as the inventive product 9) comprises: by the total weight of the brass alloy, 60-65 wt % copper, 0.05-0.5 wt % tin, and two or more elements selected from the group consisting of, by the total weight of the brass alloy, 0.1-0.7 wt % aluminum, 0.05-0.3 wt % phosphorus and 0.05-0.5 wt % manganese, and further comprises, by the total weight of the brass alloy, 0.01-0.15 wt % antimony, 0.1-0.5 wt % magnesium and/or 0.001-0.01 wt % boron, and a balance of zinc and unavoidable impurities, wherein the unavoidable impurities comprise: 0.25 wt % or less nickel, 0.15 wt % or less chrome and/or 0.25 wt % or less iron by the total weight of the brass alloy.

As compared with the inventive product 8, the inventive product 9 further comprises some unavoidable impurities, i.e., mechanical impurities of nickel, chrome and/or iron.

A lead-free bismuth-free silicon-free brass alloy with excellent cutting performance (hereinafter referred to as the inventive product 10) comprises: by the total weight of the brass alloy, 60-65 wt % copper, 0.01-0.15 wt % antimony and 0.1-0.5 wt % magnesium, and one or more element selected from the group consisting of, by the total weight of the brass alloy, 0.1-0.7 wt % aluminum, 0.05-0.5 wt % tin, 0.05-0.3 wt % phosphorus, 0.05-0.5 wt % manganese and 0.001-0.01 wt % boron, and a balance of zinc.

Whether aluminum, tin, phosphorus, manganese and/or boron should be added depends on the requirement for cutting performance of various produc. The content to be added has the same interval as that of the inventive product 3, and this is based on the same reason as that of the inventive product 3.

A lead-free bismuth-free silicon-free brass alloy with excellent cutting performance (hereinafter referred to as the inventive product 11) comprises: by the total weight of the brass alloy, 60-65 wt % copper, 0.01-0.15 wt % antimony and 0.1-0.5 wt % magnesium, and one or more element selected from the group consisting of, by the total weight of the brass alloy, 0.1-0.7 wt % aluminum, 0.05-0.5 wt % tin, 0.05-0.3 wt % phosphorus, 0.05-0.5 wt % manganese and 0.001-0.01 wt % boron, and a balance of zinc and unavoidable impurities, wherein the unavoidable impurities comprise: 0.25 wt % or less nickel, 0.15 wt % or less chrome and/or 0.25 wt % or less iron by the total weight of the brass alloy.

As compared with the inventive product 10, the inventive product 11 further comprises some unavoidable impurities, i.e., mechanical impurities of nickel, chrome and/or iron.

The invention further provides a method for fabricating brass alloy. By taking an example of the inventive product 3 as an example, the method comprises the steps of:

1) providing copper and manganese and heating to 1000-1050° C. to form a copper-manganese alloy melt;

2) decreasing the temperature of the copper-manganese alloy melt to 950-1000° C.;

3) covering the surface of copper-manganese alloy melt with a glass slagging agent;

4) adding zinc to the copper-manganese alloy melt to form a copper-manganese-zinc melt;

5) deslagging the copper-manganese-zinc melt, and adding antimony, aluminum, tin, magnesium to the brass alloy melt to form a metal melt;

6) elevating the temperature of the metal melt to 1000-1050° C., and adding boron copper alloy, phosphorus copper alloy to form a lead-free bismuth-free silicon-free brass alloy melt;

7) discharging the brass alloy melt for casting to form the brass alloy.

Preferably, in the above fabricating method, a copper-manganese alloy is provided as the precursor of copper and manganese elements.

Preferably, in the above fabricating method, the melting furnace is a high-frequency melting furnace, and the high-frequency melting furnace is provided with a furnace lining of graphite crucible.

The high-frequency melting furnace has the features of a large melting rate, a large temperature elevating rate, cleanness without pollution, and the ability of self-stirring (i.e., under the action of magnetic field lines) during melting.

In the invention, the lead-free bismuth-free silicon-free brass alloy is formed by adding various constituents in respective ratio, and then subjecting them to a process in a high-frequency melting furnace. The resulting brass alloy has a mechanical processability which is comparable with that of the existing lead-containing brass, has an excellent tensile strength, elongation rate, and dezincification resistance, and is lead-free. As a result, the brass alloy is suitable for replacing the existing lead-containing brass alloy and for producing parts like faucet and sanitary ware.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart illustrating a method for fabricating an example of the inventive product 3.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The technical solutions of the invention will be described expressly by referring to embodiments thereof.

It is not intended to limit the scope of the invention to the described exemplary embodiments. The modifications and alterations to features of the invention as described herein, as well as other applications of the concept of the invention (which will occur to the skilled in the art, upon reading the present disclosure) still fall within the scope of the invention.

In the invention, the wording “or more”, “or less” in the expression for describing values indicates that the expression comprises the relevant values.

The dezincification corrosion resistant performance measurement, as used herein, is performed according to AS-2345-2006 specification in the cast state, in which 12.8 g copper chloride is added into 1000C.0 deionized water, and the object to be measured is placed in the resulting solution for 24 hr to measure a dezincification depth. ⊚ indicates a dezincification depth of less than 100 μm; o indicates a dezincification depth between 100 μm and 200 μm; and

indicates a dezincification depth larger than 200 μm.

The cutting performance measurement, as used herein, is performed in the cast state, in which the same cutting tool is adopted with the same cutting speed and feed amount. The cutting speed is 25 m/min (meter per minute), the feed amount is 0.2 mm/r (millimeter per number of cutting edge), the cutting depth is 0.5 mm, the measurement rod has a diameter of 20 mm, and C36000 alloy is taken as a reference. The relative cutting rate is derived by measuring the cutting resistance.

The relative cutting rate =cutting resistance of C36000 alloy/cutting resistance of the sample.

⊚ indicates a relative cutting rate larger than 85%; and o indicates a relative cutting rate larger than 70%.

Both the tensile strength measurement and the elongation rate measurement, as used herein, are performed in the cast state at room temperature as an elongation measurement. The elongation rate refers to a ratio between the total deformation of gauge section after elongation ΔL and the initial gauge length L of the sample in percentage: δ=ΔL/L×100%. The reference sample is a lead-containing brass with the same state and specification, i.e., C36000 alloy.

According to measurement, the proportions for constituents of C36000 alloy are listed as follow, in the unit of weight percentage (wt %):

copper zinc bismuth antimony manganese aluminum lead iron Material No. (Cu) (Zn) (Bi) (Sb) (Mn) (Al) tin (Sn) (Pb) (Fe) C36000 alloy 60.53 36.26 0 0 0 0 0.12 2.97 0.12

FIG. 1 is a flow chart illustrating a method for fabricating an example of the inventive product 3, which comprises the steps of:

Step S100: providing copper and manganese. In this step, a copper-manganese alloy can be provided as the precursor of copper and manganese elements.

Step S102: heating the copper-manganese precursor alloy to 1000-1050° C. to form a copper-manganese alloy melt. In this step, the copper-manganese alloy can be added into the high-frequency melting furnace, and heated to melt in the melting furnace. The temperature can be elevated to 1000-1050° C., and even up to 1100° C., for 5-10 minutes, so that the copper-manganese alloy is melt into a copper-manganese alloy melt. With these actions, it is possible to prevent the melt copper manganese from absorbing a lot of external gases (due to a too high temperature), which may otherwise result in cracking in the molded alloy.

Step S104: decreasing the temperature of the copper-manganese alloy melt to 950-1000° C. In this step, when the temperature in the melting furnace is elevated to 1000-1050° C. for a durationi of 5-10 minutes, the power supply of the high-frequency melting furnace is turned off, so that the temperature in the melting furnace is reduced to 950-1000° C., while the copper-manganese alloy melt is maintained in the melt state.

Step S106: covering the surface of copper-manganese alloy melt with a glass slagging agent. In this step, the surface of copper-manganese alloy melt is covered with the glass slagging agent at 950-1000° C. This step can effectively prevent the melt from contacting the air, and prevent zinc to be added in the next step from boiling and evaporating due to melting at a high temperature of 950-1000° C.

Step S108: adding zinc to the copper-manganese alloy melt to form a copper-manganese-zinc melt. In this step, zinc is added to the melting furnace, and is immersed into the copper-manganese alloy melt, so that zinc is sufficiently melt in the copper-manganese alloy melt to form a copper-manganese-zinc melt.

Step S110: deslagging the copper-manganese-zinc melt. In this step, the copper-manganese-zinc melt can be stirred and mixed under the action high-frequency induction, and then the slagging agent can be removed. Then, the copper-manganese-zinc melt is deslagged with a deslagging agent.

Step S112: adding antimony, aluminum, tin, and magnesium to the copper-manganese-zinc melt to form a metal melt. In this step, copper antimony precursor alloy, copper aluminum precursor alloy, copper tin precursor alloy, and copper magnesium alloy can be added to the copper-manganese-zinc melt.

Step S114: elevating the temperature of the metal melt to 1000-1050° C., and adding copper boron alloy and phosphorus copper alloy to form a lead-free bismuth-free silicon-free brass alloy melt.

Step S116: discharging the brass alloy melt for casting to form the brass alloy. In this step, the brass alloy melt is stirred evenly, the discharging temperature is controlled at 1000-1050° C., and finally the brass alloy melt is discharged to casting a lead-free bismuth-free silicon-free brass alloy which exhibits good processability, dezincification resistance, and mechanical performance.

Embodiment 1

Table 1-1 lists inventive products 1 with 5 different constituents which are fabricated with the above process, which are respectively numbered as 1001-1005, each constituent being in the unit of weight percentage (wt %).

TABLE 1-1 No. copper (Cu) zinc (Zn) magnesium (Mg) antimony (Sb) 1001 62.605 36.839 0.254 0.010 1002 64.355 34.819 0.402 0.022 1003 65.000 34.198 0.100 0.150 1004 60.000 39.373 0.122 0.103 1005 61.005 38.040 0.500 0.143

Measurements about cutting performance, dezincification corrosion resistant performance, tensile strength, and elongation rate are performed on alloys with the above constituents in the cast state at room temperature, and the reference sample is a lead-containing brass with the same state and specification, i.e., C36000 alloy.

Results of the measurements about tensile strength, elongation rate, cutting performance, and dezincification corrosion resistant performance are listed as follow:

TENSILE DEZINCIFI- RELATIVE STRENGTH ELONGATION CATION CUTTING No. (N/mm²) RATE (%) LAYER RATE 1001 348 12 ⊚ ∘ 1002 367 11 ⊚ ⊚ 1003 275 21 ∘ ⊚ 1004 281 13 ∘ ∘ 1005 328 15 ∘ ⊚ C36000 alloy 394 9

⊚

Embodiment 2

Table 2-1 lists inventive products 2 with 5 different constituents which are fabricated with the above process, which are respectively numbered as 2001-2005, each constituent being in the unit of weight percentage (wt %).

TABLE 2-1 magnesium antimony manganese phosphorus No. copper (Cu) zinc (Zn) (Mg) (Sb) (Mn) (P) 2001 60.000 39.044 0.352 0.012 — 0.300 2002 64.501 34.340 0.403 0.010 0.302 0.152 2003 63.522 35.226 0.500 0.150 0.050 — 2004 65.000 34.144 0.220 0.132 0.252 0.050 2005 61.522 37.173 0.100 0.051 0.500 0.252

Measurements about cutting performance, dezincification corrosion resistant performance, tensile strength, and elongation rate are performed on alloys with the above constituents in the cast state at room temperature, and the reference sample is a lead-containing brass with the same state and specification, i.e., C36000 alloy.

Results of the measurements about tensile strength, elongation rate, cutting performance, and dezincification corrosion resistant performance are listed as follow:

TENSILE DEZINCIFI- RELATIVE STRENGTH ELONGATION CATION CUTTING No. (N/mm²) RATE (%) LAYER RATE 2001 368 12 ⊚ ⊚ 2002 367 11 ⊚ ⊚ 2003 335 21 ⊚ ⊚ 2004 381 13 ⊚ ⊚ 2005 308 15 ⊚ ∘ C36000 alloy 394 9

⊚

Embodiment 3

Table 3-1 lists inventive products 3 with 8 different constituents which are fabricated with the above process, which are respectively numbered as 3001-3008, each constituent being in the unit of weight percentage (wt %).

TABLE 3-1 copper magnesium antimony aluminum manganese phosphorus boron No. (Cu) zinc (Zn) (Mg) (Sb) (Al) tin (Sn) (Mn) (P) (B) 3001 63.502 35.309 0.103 0.018 0.500 0.052 0.050 0.173 0.001 3002 60.000 37.758 0.500 0.047 0.522 0.500 0.051 0.252 — 3003 65.221 33.233 0.487 0.010 0.622 0.050 0.032 0.050 0.010 3004 63.523 34.577 0.273 0.095 0.303 0.351 0.067 0.300 0.008 3005 63.210 34.673 0.100 0.032 0.700 — 0.500 0.178 0.004 3006 65.000 33.244 0.211 0.150 0.352 0.235 0.253 — 0.003 3007 60.351 38.339 0.195 0.111 — 0.111 0.488 0.203 — 3008 60.132 38.716 0.107 0.100 0.100 — 0.231 0.210 0.002

Measurements about cutting performance, dezincification corrosion resistant performance, tensile strength, and elongation rate are performed on alloys with the above constituents in the cast state at room temperature, and the reference sample is a lead-containing brass with the same state and specification, i.e., C36000 alloy.

Results of the measurements about tensile strength, elongation rate, cutting performance, and dezincification corrosion resistant performance are listed as follow:

TENSILE DEZINCIFI- RELATIVE STRENGTH ELONGATION CATION CUTTING No. (N/mm²) RATE (%) LAYER RATE 3001 368 12 ⊚ ⊚ 3002 357 11 ⊚ ⊚ 3003 335 13 ⊚ ⊚ 3004 381 11 ⊚ ⊚ 3005 388 10 ⊚ ⊚ 3006 363 11 ⊚ ⊚ 3007 323 15 ⊚ ∘ 3008 319 17 ∘ ⊚ C36000 alloy 394 9

⊚

Embodiment 4

Table 4-1 lists inventive products 4 with 8 different constituents which are fabricated with the above process, which are respectively numbered as 4001-4008, each constituent being in the unit of weight percentage (wt %).

TABLE 4-1 copper magnesium antimony manganese aluminum phosphorus boron No. (Cu) zinc (Zn) (Mg) (Sb) (Mn) (Al) tin (Sn) (P) (B) 4001 61.833 37.142 0.302 0.011 0.050 0.155 0.050 0.155 — 4002 62.501 36.327 0.253 0.015 — 0.200 0.355 0.050 0.008 4003 60.000 38.425 0.271 0.122 0.053 0.100 0.500 0.179 0.010 4004 65.000 32.643 0.500 0.010 0.253 0.534 0.454 0.300 0.005 4005 63.550 34.411 0.233 0.045 0.500 0.653 0.300 — 0.006 4006 60.221 37.902 0.244 0.150 — 0.700 — 0.222 0.009 4007 62.324 35.999 0.135 0.135 0.488 — 0.183 0.214 — 4008 64.049 34.511 0.100 0.052 0.325 0.454 0.143 0.063 0.001

Measurements about cutting performance, dezincification corrosion resistant performance, tensile strength, and elongation rate are performed on alloys with the above constituents in the cast state at room temperature, and the reference sample is a lead-containing brass with the same state and specification, i.e., C36000 alloy.

Results of the measurements about tensile strength, elongation rate, cutting performance, and dezincification corrosion resistant performance are listed as follow:

TENSILE DEZINCIFI- RELATIVE STRENGTH ELONGATION CATION CUTTING No. (N/mm²) RATE (%) LAYER RATE 4001 368 12 ⊚ ⊚ 4002 327 11 ⊚ ⊚ 4003 335 21 ⊚ ⊚ 4004 381 13 ⊚ ⊚ 4005 388 10 ⊚ ⊚ 4006 377 13 ⊚ ⊚ 4007 301 10 ⊚ ⊚ 4008 391 9 ⊚ ⊚ C36000 alloy 394 9

⊚

Embodiment 5

Table 5-1 lists inventive products 5 with 8 different constituents which are fabricated with the above process, which are respectively numbered as 5001-5008, each constituent being in the unit of weight percentage (wt %).

TABLE 5-1 copper magnesium antimony manganese aluminum phosphorus boron No. (Cu) zinc (Zn) (Mg) (Sb) (Mn) (Al) tin (Sn) (P) (B) 5001 61.800 37.014 0.231 0.023 0.054 0.100 0.500 0.066 0.010 5002 62.472 36.526 0.207 0.010 0.108 — 0.325 0.052 — 5003 60.000 38.549 0.100 0.113 0.500 — 0.486 0.050 — 5004 62.731 36.021 0.137 0.141 0.192 0.118 0.050 0.194 0.005 5005 62.498 35.400 0.273 0.150 — 0.700 0.416 — 0.001 5006 64.032 34.578 0.186 0.013 0.067 0.328 0.377 0.104 0.004 5007 65.000 33.937 0.262 0.109 0.050 — 0.337 0.103 — 5008 64.855 32.526 0.500 0.072 0.452 0.676 — 0.300 0.008

Measurements about cutting performance, dezincification corrosion resistant performance, tensile strength, and elongation rate are performed on alloys with the above constituents in the cast state at room temperature, and the reference sample is a lead-containing brass with the same state and specification, i.e., C36000 alloy.

Results of the measurements about tensile strength, elongation rate, cutting performance, and dezincification corrosion resistant performance are listed as follow:

TENSILE DEZINCIFI- RELATIVE STRENGTH ELONGATION CATION CUTTING No. (N/mm²) RATE (%) LAYER RATE 5001 368 12 ⊚ ⊚ 5002 297 11 ⊚ ⊚ 5003 335 21 ⊚ ⊚ 5004 371 13 ⊚ ⊚ 5005 328 15 ⊚ ⊚ 5006 358 13 ⊚ ⊚ 5007 383 12 ⊚ ⊚ 5008 385 10 ⊚ ⊚ C36000 alloy 394 9

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Embodiment 6

Table 6-1 lists inventive products 6 with 8 different constituents which are fabricated with the above process, which are respectively numbered as 6001-6008, each constituent being in the unit of weight percentage (wt %).

TABLE 6-1 copper magnesium antimony manganese aluminum phosphorus boron nickel chrome iron No. (Cu) zinc (Zn) (Mg) (Sb) (Mn) (Al) tin (Sn) (P) (B) (Ni) (Cr) (Fe) 6001 61.030 37.482 0.332 0.133 — 0.132 0.500 0.080 0.008 — — 0.003 6002 64.501 33.966 0.227 0.120 0.500 — 0.076 0.050 0.009 — 0.144 0.007 6003 63.000 35.380 0.150 0.010 0.321 0.100 0.400 0.222 0.001 0.005 0.098 0.023 6004 62.231 36.218 0.100 0.032 — 0.602 — 0.300 0.010 — 0.007 — 6005 62.875 34.945 0.432 0.088 0.431 0.540 0.050 — 0.007 0.021 — 0.011 6006 65.000 33.696 0.378 0.117 0.311 — 0.087 0.077 — 0.009 0.112 0.013 6007 63.740 33.472 0.436 0.150 0.101 0.700 0.342 0.093 0.005 0.250 0.150 — 6008 60.000 37.735 0.500 0.093 0.050 0.687 — 0.103 0.009 0.007 — 0.250

Measurements about cutting performance, dezincification corrosion resistant performance, tensile strength, and elongation rate are performed on alloys with the above constituents in the cast state at room temperature, and the reference sample is a lead-containing brass with the same state and specification, i.e., C36000 alloy.

Results of the measurements about tensile strength, elongation rate, cutting performance, and dezincification corrosion resistant performance are listed as follow:

TENSILE DEZINCIFI- RELATIVE STRENGTH ELONGATION CATION CUTTING No. (N/mm²) RATE (%) LAYER RATE 6001 355 13 ⊚ ⊚ 6002 398 10 ⊚ ⊚ 6003 391 11 ⊚ ⊚ 6004 337 13 ⊚ ⊚ 6005 322 16 ⊚ ⊚ 6006 383 13 ⊚ ⊚ 6007 337 12 ⊚ ⊚ 6008 301 17 ⊚ ⊚ C36000 alloy 394 9

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Embodiment 7

Table 7-1 lists inventive products 7 with 8 different constituents which are fabricated with the above process, which are respectively numbered as 7001-7008, each constituent being in the unit of weight percentage (wt %).

TABLE 7-1 manganese phosphorus No. copper (Cu) zinc (Zn) (Mn) aluminum (Al) tin (Sn) (P) 7001 62.000 37.596 0.050 0.207 0.050 0.095 7002 63.431 35.903 0.223 0.332 0.109 — 7003 61.118 38.160 0.217 0.100 0.403 — 7004 60.000 39.525 — 0.157 0.233 0.083 7005 63.043 35.974 0.431 — 0.500 0.050 7006 65.000 33.620 0.500 0.541 0.337 — 7007 62.043 36.929 0.087 0.432 0.207 0.300 7008 64.754 33.867 0.093 0.700 0.331 0.253

Measurements about cutting performance, dezincification corrosion resistant performance, tensile strength, and elongation rate are performed on alloys with the above constituents in the cast state at room temperature, and the reference sample is a lead-containing brass with the same state and specification, i.e., C36000 alloy.

Results of the measurements about tensile strength, elongation rate, cutting performance, and dezincification corrosion resistant performance are listed as follow:

TENSILE DEZINCIFI- RELATIVE STRENGTH ELONGATION CATION CUTTING No. (N/mm²) RATE (%) LAYER RATE 7001 311 12 ⊚ ⊚ 7002 352 11 ⊚ ⊚ 7003 365 21 ⊚ ⊚ 7004 334 13 ⊚ ⊚ 7005 295 11 ∘ ⊚ 7006 293 10 ∘ ⊚ 7007 354 12 ⊚ ⊚ 7008 389 10 ⊚ ⊚ C36000 alloy 394 9

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Embodiment 8

Table 8-1 lists inventive products 8 with 8 different constituents which are fabricated with the above process, which are respectively numbered as 8001-8008, each constituent being in the unit of weight percentage (wt %).

TABLE 8-1 copper magnesium antimony manganese aluminum phosphorus No. (Cu) zinc (Zn) (Mg) (Sb) (Mn) (Al) tin (Sn) (P) boron (B) 8001 63.120 35.186 0.450 0.150 0.055 0.350 0.050 0.087 — 8002 60.000 39.184 0.100 — 0.105 0.231 0.377 — 0.001 8003 61.157 37.521 0.243 0.050 0.374 0.100 0.094 0.050 0.009 8004 62.300 36.508 — 0.010 — 0.493 0.178 0.211 0.008 8005 62.138 35.691 0.500 0.130 0.109 0.700 0.203 0.300 0.007 8006 65.000 33.526 0.337 — 0.500 0.337 0.095 0.198 0.005 8007 63.433 34.703 0.295 0.075 0.089 0.205 0.500 0.188 0.010 8008 63.064 35.416 0.250 0.053 0.050 — 0.498 0.067 —

Measurements about cutting performance, dezincification corrosion resistant performance, tensile strength, and elongation rate are performed on alloys with the above constituents in the cast state at room temperature, and the reference sample is a lead-containing brass with the same state and specification, i.e., C36000 alloy.

Results of the measurements about tensile strength, elongation rate, cutting performance, and dezincification corrosion resistant performance are listed as follow:

TENSILE DEZINCIFI- RELATIVE STRENGTH ELONGATION CATION CUTTING No. (N/mm²) RATE (%) LAYER RATE 8001 374 12 ⊚ ⊚ 8002 299 24 ∘ ⊚ 8003 310 19 ⊚ ⊚ 8004 311 13 ⊚ ⊚ 8005 399 15 ⊚ ⊚ 8006 384 10 ⊚ ⊚ 8007 367 11 ⊚ ⊚ 8008 353 14 ⊚ ⊚ C36000 alloy 394 9

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Embodiment 9

Table 9-1 lists inventive products 9 with 8 different constituents which are fabricated with the above process, which are respectively numbered as 9001-9008, each constituent being in the unit of weight percentage (wt %).

TABLE 9-1 copper magnesium antimony manganese aluminum phosphorus boron nickel chrome iron No. (Cu) zinc (Zn) (Mg) (Sb) (Mn) (Al) tin (Sn) (P) (B) (Ni) (Cr) (Fe) 9001 60.321 38.107 0.453 0.078 — 0.293 0.085 0.056 — — — 0.007 9002 61.050 37.387 0.100 0.150 0.067 — 0.050 0.143 0.009 0.250 0.112 0.132 9003 62.223 36.093 0.118 0.053 0.500 0.100 0.055 — 0.001 0.148 0.008 0.201 9004 62.350 36.702 0.119 — 0.109 0.105 0.155 0.050 0.010 — 0.150 0.250 9005 65.000 32.675 0.500 0.010 0.237 0.700 0.207 0.287 0.007 0.087 — — 9006 64.487 33.545 0.373 0.092 0.498 0.583 0.211 — 0.005 — 0.006 — 9007 60.000 38.051 — 0.147 — 0.473 0.500 0.300 0.004 0.009 0.103 0.113 9008 63.185 35.314 0.208 0.118 0.050 0.373 0.321 0.217 — 0.007 0.001 0.006

Measurements about cutting performance, dezincification corrosion resistant performance, tensile strength, and elongation rate are performed on alloys with the above constituents in the cast state at room temperature, and the reference sample is a lead-containing brass with the same state and specification, i.e., C36000 alloy.

Results of the measurements about tensile strength, elongation rate, cutting performance, and dezincification corrosion resistant performance are listed as follow:

TENSILE DEZINCIFI- RELATIVE STRENGTH ELONGATION CATION CUTTING No. (N/mm²) RATE (%) LAYER RATE 9001 310 12 ⊚ ⊚ 9002 318 11 ⊚ ⊚ 9003 320 21 ⊚ ⊚ 9004 341 13 ⊚ ⊚ 9005 387 15 ⊚ ⊚ 9006 379 13 ⊚ ⊚ 9007 311 12 ⊚ ⊚ 9008 386 10 ⊚ ⊚ C36000 alloy 394 9

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Embodiment 10

Table 10-1 lists inventive products 10 with 8 different constituents which are fabricated with the above process, which are respectively numbered as 10001-10008, each constituent being in the unit of weight percentage (wt %).

TABLE 10-1 copper magnesium antimony manganese aluminum phosphorus No. (Cu) zinc (Zn) (Mg) (Sb) (Mn) (Al) tin (Sn) (P) boron (B) 10001 61.099 38.035 0.454 0.054 0.056 — — — — 10002 62.413 36.677 0.500 0.010 0.050 — 0.050 — 0.008 10003 60.073 39.148 0.198 0.076 — 0.203 — — — 10004 60.000 38.183 0.231 0.075 0.432 0.100 0.310 0.067 — 10005 60.043 37.982 0.100 0.150 0.500 0.507 0.106 0.050 0.010 10006 63.661 34.510 0.307 0.100 0.108 0.700 — 0.203 0.009 10007 65.000 33.440 0.273 0.054 0.310 0.432 0.088 — 0.001 10008 64.398 33.251 0.203 0.073 0.298 0.670 0.500 0.300 0.005

Measurements about cutting performance, dezincification corrosion resistant performance, tensile strength, and elongation rate are performed on alloys with the above constituents in the cast state at room temperature, and the reference sample is a lead-containing brass with the same state and specification, i.e., C36000 alloy.

Results of the measurements about tensile strength, elongation rate, cutting performance, and dezincification corrosion resistant performance are listed as follow:

TENSILE DEZINCIFI- RELATIVE STRENGTH ELONGATION CATION CUTTING No. (N/mm²) RATE (%) LAYER RATE 10001 301 22 ⊚ ⊚ 10002 323 11 ⊚ ⊚ 10003 300 20 ⊚ ⊚ 10004 311 13 ⊚ ⊚ 10005 320 10 ⊚ ⊚ 10006 379 13 ⊚ ⊚ 10007 387 12 ⊚ ⊚ 10008 396 10 ⊚ ⊚ C36000 alloy 394 9

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Embodiment 11

Table 11-1 lists inventive products 11 with 8 different constituents which are fabricated with the above process, which are respectively numbered as 11001-11008, each constituent being in the unit of weight percentage (wt %).

TABLE 11-1 copper zinc magnesium antimony manganese aluminum phosphorus boron nickel chrome iron No. (Cu) (Zn) (Mg) (Sb) (Mn) (Al) tin (Sn) (P) (B) (Ni) (Cr) (Fe) 11001 61.113 38.185 0.105 0.130 — — 0.079 0.067 — — — 0.021 11002 60.002 38.030 0.100 0.111 0.057 0.700 0.204 0.050 — 0.085 0.111 0.250 11003 60.000 39.013 0.213 0.105 0.050 — — 0.134 0.001 0.250 — 0.034 11004 64.322 33.670 0.322 0.010 0.107 0.455 0.500 0.233 0.007 — 0.084 — 11005 65.000 33.355 0.206 0.059 — 0.100 0.344 — 0.010 0.101 0.015 0.210 11006 63.122 34.726 0.500 0.031 0.500 0.104 0.050 0.300 0.009 0.044 0.009 0.005 11007 62.397 35.662 0.493 0.044 0.432 0.233 — — 0.005 0.197 0.030 0.007 11008 64.920 32.869 0.405 0.150 0.210 0.653 0.133 0.095 0.008 0.007 — —

Measurements about cutting performance, dezincification corrosion resistant performance, tensile strength, and elongation rate are performed on alloys with the above constituents in the cast state at room temperature, and the reference sample is a lead-containing brass with the same state and specification, i.e., C36000 alloy.

Results of the measurements about tensile strength, elongation rate, cutting performance, and dezincification corrosion resistant performance are listed as follow:

TENSILE DEZINCIFI- RELATIVE STRENGTH ELONGATION CATION CUTTING No. (N/mm²) RATE (%) LAYER RATE 11001 317 13 ⊚ ⊚ 11002 320 12 ⊚ ⊚ 11003 305 18 ⊚ ⊚ 11004 374 13 ⊚ ⊚ 11005 378 15 ⊚ ⊚ 11006 381 13 ⊚ ⊚ 11007 369 12 ⊚ ⊚ 11008 391 10 ⊚ ⊚ C36000 alloy 394 9

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As can be seen, the lead-free bismuth-free silicon-free brass alloy of the invention can be formed by adding various constituents in respective ratio, and then subjecting them to a process in a high-frequency melting furnace. The resulting brass alloy has a mechanical processability which is comparable with that of the existing lead-containing brass, has an excellent tensile strength, elongation rate, and dezincification resistance, and is lead-free. As a result, the brass alloy is suitable for replacing the existing lead-containing brass alloy and for producing parts like faucet and sanitary ware.

Although the invention has been described with respect to embodiments thereof, these embodiments do not intend to limit the invention. The ordinary skilled in the art can made modifications and changes to the invention without departing from the spirit and scope of the invention. Thus, the protection of the invention is defined by the appended claims. 

1. A lead-free bismuth-free silicon-free brass alloy with excellent cutting performance, characterized by comprising: by the total weight of the brass alloy, 60-65 wt % copper, 0.01-0.15 wt % antimony, 0.1-0.5 wt % magnesium, and a balance of zinc.
 2. The brass alloy of claim 1, characterized by further comprising: 0.05-0.3 wt % phosphorus and/or 0.05-0.5 wt % manganese by the total weight of the brass alloy.
 3. The brass alloy of claim 1, characterized by further comprising: 0.05-0.5 wt % manganese, 0.1-0.7 wt % aluminum, 0.05-0.5 wt % tin, 0.05-0.3 wt % phosphorus and/or 0.001-0.01 wt % boron by the total weight of the brass alloy.
 4. The brass alloy of claim 3, characterized in that a total content of manganese, aluminum, tin, phosphorus and/or boron is not larger than 2 wt % of the total weight of the brass alloy.
 5. The brass alloy of claim 4, characterized in that a total content of manganese, aluminum, tin, phosphorus and/or boron is not less than 0.2 wt % of the total weight of the brass alloy.
 6. The brass alloy of claim 3, characterized by further comprising: unavoidable impurities which comprise, by the total weight of the brass alloy, 0.25 wt % or less nickel, 0.15 wt % or less chrome and/or 0.25 wt % or less iron.
 7. A lead-free bismuth-free silicon-free brass alloy with excellent cutting performance, characterized by comprising: by the total weight of the brass alloy, 60-65 wt % copper, 0.05-0.5 wt % tin, and two or more elements selected from the group consisting of 0.1-0.7 wt % aluminum, 0.05-0.3 wt % phosphorus and 0.05-0.5 wt % manganese by the total weight of the brass alloy, and a balance of zinc.
 8. The brass alloy of claim 7, characterized by further comprising: 0.01-0.15 wt % antimony, 0.1-0.5 wt % magnesium and/or 0.001-0.01 wt % boron by the total weight of the brass alloy.
 9. The brass alloy of claim 8, characterized by further comprising: unavoidable impurities which comprise, by the total weight of the brass alloy, 0.25 wt % or less nickel, 0.15 wt % or less chrome and/or 0.25 wt % or less iron.
 10. A lead-free bismuth-free silicon-free brass alloy with excellent cutting performance, characterized by comprising: by the total weight of the brass alloy, 60-65 wt % copper, 0.01-0.15 wt % antimony and 0.1-0.5 wt % magnesium, and one or more element selected from the group consisting of 0.1-0.7 wt % aluminum, 0.05-0.5 wt % tin, 0.05-0.3 wt % phosphorus, 0.05-0.5 wt % manganese and 0.001-0.01 wt % boron by the total weight of the brass alloy, and a balance of zinc.
 11. The brass alloy of claim 10, characterized by further comprising: unavoidable impurities which comprise, by the total weight of the brass alloy, 0.25 wt % or less nickel, 0.15 wt % or less chrome and/or 0.25 wt % or less iron. 